Rectilinear induction motor



7n s 1 v This invention relates to an improvement in alternating current motors and more particularLv to those of the rectilinear type.

The preferred embodiment o! this invention 5 provides a motor having a field structure and translator. The field structure is arranged with a central longitudinal opening which spaces apart. substantially duplicate elements. The translator lies in the opening between these ele- `1g ments and, being the driven element, may be linked in any convenient and practicable manner to performer. given work.'

The principal. object of the invention is to provide a rectilinear motor having application 'l5' to and. being adapted to produce a rectilinear driving force i'or use in connection with many kinds'o! work.

Another object of the invention is to provide a rectilinear motor-having structure adapted 'zo' to reduce, to a minimum, all noises incident to the operationthereof." f A further object of the invention is to provide a motor of this type; the xed elements ot which are completely enclosed by a supporting strucgg ture adapted to prevent physical distortion duringoperatiom y' Y A still further object oi' thefinventon is to provides. rectilinearmotor having relatively movable elements which may be readily applied 39 to and adapted to actuate a sliding door, one element being mounted on the enclosure and the other element on the door.

Other and further objects of 'the invention will be more clearly understood from a considera- 35 tion 'of the following specincation which is taken in conjunction with the accompanying drawing,- andmwmgn. l..

Fig. 1 is a rear elevation of one modiilcation oi this invention applied to and adapted to actu- `mateaslidingdoor;` l' `Fig. 2 is an enlarged vertical sectional view. taken substantially through the-center of Figure 1. showing the door suspension and motor attach '4S Pimlisauenlargedsideelevationotthe motor, parts being broken away to reveal certain details of-thestructurethereotz -A Pig.4 4 is a fragmentary horizontal sectional view oi' the motonbeing taken substantially on so' the une 4--4 irrigare z and snows che method- UNITED STATES ,PATENTQFFICB u naornmnannmucnox Moroltfn 411- Edwin n mae, cambridge, Mm, am se ff u A Dahlstrom Metallic Door Gompany. town,lI.Y.,acorporationotNewYork' .il

Application may 21,1931. serum. More: :tu '.f. 'A 1 14 Claims. (CI: "Aff-...Jl ,K .""I j Figisatragmentaryplanviewahowingtll method of joining the motor elements together; Fig. 7 is a. diagrammatic showing of s reversing switch that may be used in exciting the Attention is directed to the fact that the drawlng discloses a rectilinear induction motorhawing a neld structure which includes two reverse!! disposed corre and coil groups, between which an armature or translator ia located. It will 'be Q, understood that the present invention contemplates the use also of a motor of this type having but one core and coil group, adjacent the proper face oi' which the armature is located. In other words, each neld group acts independently on the n armatin'e 'and consequently elimination of one of the groups merely results in a motor ofeon'n siderably less eiliciency and power. The-purpose of this arrangement may be more readily understood by considering the structure in' Figure 2 'oi u the drawing wherein the depth oi'- the enclosure structure is suiiicient te receive a neld struc-.tml comprised of two spaced core and coil groupe; In building construction it is frequently Ioimd necessarytoreduce thisdeptharximdersuch conditions a motor having one or more core and coil groups adjacent only one face of the arm* ture may be satisfactorily utilized. f. Referring to the drawing, the invention, generally. indicated by the reference numeral 1U. is u, shown mounted for use and adapted to operate n slidingdoor 11. Attached to the upperedge o! the doorisapendent plate 12 nwhich rollersM are located. The rollers 14 are mounted on a track i5 which, through brackets 1?-, is secured n, to anenclosure 18. Y, The motor comprises a eld structme v20 and armature or translator 21( The armature il; formed with a horizontal hangen by which it b secured through bolts 23, to the pendent plate g.. 12. Ir:v the present of the invention, the armature is shown to project beyond one vertiealedge et thedoors distmceapproximately thewidthotsaiddoor. v'L'lifelengthotheornxlturaliowevenianeceesarilygwernedonly bythe 1g. extent oi' translation required to perform a given work. The vertical portion- 25 projects prefer-y ably upwardLv into a longitudinal slet or openingl formedcentra'lly-ot the mdd structure and b causedtemove'inoriedirectionorthasretlnsloll tially identical spaced field groups. The casing is comprised of two vertical wall elements 28 which are connected along their upper edge by a plate 29, through bolts 30. The plate 29 con- 6 stitutes the means by which the eld structure is supported and, as found convenient in the present instance, the ends thereof are projected slightly beyond the vertical ends of. the eld structure, being secured to a horizontal flange of the en- 10 closure 18 by bolts 31. The side walls 28 terminate, along their lower edges in inturned fianges 33. The ends of 'the side walls are likewise terminated by inturned flanges 34. When the side walls are spacedly connected in the manner above described, the adjacent inner edges of flanges 33 and 34 of each of said walls are spaced apart to provide a vertical longitudinally extending slot 36 in the casing. Uniformly spaced vertical slcts 37 are made in the walls 28 of the casing. The slots are preferably wedge shaped in' cross-section, being terminated at their upper ends in larger rectangular slots 38. These slots are for the purpose of interlocking stacks of laminations with each of the vertical walls 28, as

9,5 will be more fully described.

In the field structure are duplicate groups which comprise windings 40 and 41 located in cores 42. Since the structural details of each group are identical, only one will be described in 30 detail. The laminated core 42 is comprised o1' stamped strips 43 which are stacked to obtain the desired height. These strips contain evenly spaced substantially oval shaped slots 45 which are formed by similarly spaced teeth 46. The projections diverge at their ends to form skirts 47,' the vertical edges of which constitute pole faces. Horizontally adjacent teeth are separated by a narrow slot 48 which opens into the oval slot 45. The outer vertical edge of each strip is 40? formed with a number of keys 50 corresponding to the number of slots 37 in the casing wall 28. In assembling these strips in the casing a retaining and supporting plate 51 is welded or otherwise suitably joined to the wall 28, the upper edge of 4s; said plate being horizontally aligned with the bot- 'tom wall of each of the slots 37. The keys 50 of the'strips 43 are admitted to the wedge shaped slots 37 through the rectangular slot 38. being dropped in place, one piled on the other until the 5o' desired core height is reached. The lowermost strip rests upon the plate 51. To prevent loosening of the stacked strips, an upper plate 52 is provided which rests upon the uppermost strip and issecuredtothecasingwall 28 inamanner 55 similar to the plate 51. This upper plate prevents dislodgment of the strips 43 as well as constituting a support to said strips should the upright position of the field structure be reversed to that showninthedrawing.'-

s T The identical windings 40 and 41 are each comprised of a plurality of coils 54. One vertical .edge of the coil adjacent the end of the core is located inandpartlyllstherstcoreslot. Thiscoil carries over the next adjacent slot and the other 86E vertical edge thereof lies in the third slot 45 from theend.'1usofarasthiscoilisconcerned,the first two pole faces, although spaced apart by the slot 48 in the core, constitute a single pole. Thesecondcoilismountedwithoneedgeinthesec- 20S ond slot 45, the other edge lyingin the fourth slot.. 'I'he third coil is arranged with one edge in the space left unoccupied by the adjacent end of the first coil namely the third slot. the other edgeofthiscoillyinginthefthslot. Thiscoil JI! arrangementcontinues in this fashionto the end of the core. In constructing a motor of this type a denite relationship between size of coils, core slots and core depth isv established in order that when the elements are assembled they will result in a strong and compact unit of suitable electrical characteristics.

It will be noten that the inner vertical edges of cores, 42 approach eachother more closely than 'do the inner edges of the casing flanges 33 and 34. Thus the slot 36, defined by the flanges od the casing, is still further reduced to form a alot 55. dened by the adjacent core edges. The armature 21 is adapted to lie within the slot 55, being moved in one direction or another relative to the field structure by reason of a magnetic force which is set up when the coils are energized from a suitable source of alternating current supply.

Attention is particularly directed to the -fact that a motor of this type is capable of producing a considerable driving force and, as is the case with all stationary elements of a rectilinear niotor, the eld structure must be supported in'. manner to .prevent any twisting or weaving-of the elements thereof during operation. This is particularly true, since the slot 55 through which 00 the armature moves, allows only slight clearance in order that the impelling forces may more. emciently affect the armature. -Should rthe eld structure become slightly twisted or out of yalignment, the armatlne would drag when passing Q5 therethrough, resulting in wear both on the am? ature and pole faces and would also produce. an undesirable noise. To prevent this twisting, the casing 27 is flanged both at its ends and along the bottom edge. These flanges so rigidify the casing up that no appreciable variation in the `width of the slot 55 occurs during operation of the motor, .L

A rectilinear motor of this type, when directly applied as the driving force to operate a sliding door, is best arranged with the eld structure, which is generally U-shaped, supported along the base of the U. The reason for this'is obvious since the eld structure may be likened to a tuning fork which, when vibrations are set up tend to vary the relative gap or space between prongs.' Since 130 electrical vibrations set up by passingl current through the coils 54 tends to change the width of the slot 55, it becomes evident that a rigid casing` in which to spacedly mount these elements is der. sirable. A f j While applicant has shown but one modica-e tion of his invention for use in connection with the operation o f a sliding door, it is obvious to those skilled in the art that other modifications or applications may be made without departing from the spirit and scope of the invention e1 set forth in the hereunto annexed claims.- if :1;:

-Having thus set forth my invention what; I claim as new and for which I desire protectionA byLettersPatentis: :.v

. L'A rectilinear induction motor comprising two core elements, walls de ning slots;lnsaid, elements, coils mounted in said slots. keys integral with said core elements, a casing enclosing said elements, receiving means in said casing forsaid 150 keys. said meats retaining said elements in said casing, adjacent faces of said elements defining l. longitudinal passageway. walls in said casing denning a longitudinal slot, and a separately ported armatme in said passageway andsaid slot.v 1 45 i2. A casing enel-:sing the iield structure of a. rectilinear induction motorcomprising two par-J allel elements. a plate engaged with and connecting adjacent edges of said elements, means terminating the free edges of said elementqsaiddg means serving to rigidify said casing and prevent twisting or weaving of the elements of said Iield structure and said casing during operation of said motor.

3. A rectilinear induction motor having a polyphase iield structure and an armature, said eld structure being mounted on and secured to a suitable xed member, said armature being mounted on a movable member, projecting into said eld structure and guided for linear motion relative to said fixed member, said amature being dependent for support and maintenance in operative position relative to 'said eld structure upon said movable member and its guiding means.

4. A rectilinear induction motor having a eld structure and an armature, said field structure and amature being separately and removably mounted one on each of two relatively movable and relatively guided members, the guides of said members being suitable to maintain said field structure and said armature in operative spaced relationship whereby physical vibration in the elements of said field structure cannot be transmitted to said armature.

5. A rectilinear induction motor comprising a stationary eld structure, an armature mounted on a movable supporting member, said armature projecting into a longitudinal opening in said eld structure, said supporting member having guide means for maintaining said armature in spaced operative relationship to the walls of the opening in said field structure, and means for energzing said field structure to produce a traveling magnetic eld whereby to move said armature and said movable supporting member relative to said eld structure.

6. A rectilinear induction motor comprising a pair of oppositely disposed core and coil groups, a casing enclosing said groups, means securing said groups to the walls of said casing, the inn'er faces of said groups dening an air gap, and further means terminating the free edges of said casing, said further means maintaining the width of said air gap constant throughout its length whereby a separately supported armature may be inserted into said air gap for unimpeded translation relative to said core and coil groups.

7. A rectilinear induction motor comprising a pair of oppostely disposed core and coil groups, a casing enclosing said groups, means securing said groups to the walls of said casing, the inner faces of said groups defining an air gap, inturned flanges terminating the free edgesv of said casing, said flanges maintaining the width of said air gap constant throughout the length of said core and coil groups whereby a separateLv supported armature may be inserted into said air gap for unimpeded translation relative to said core and coil groups.

8. A rectilinear induction motor comprising a pair of spaced oppositel'y disposed core and coil groups, a casing enclosing said 'groups having a series of vertical slots, means on said core groups interlocking with the walls of said slots to prevent lateral displacement of said core groups relative to said casing, and further means for secur` ing said c ore group means against vertical displacement from said casing slots. A'

9. A rectilinear induction motor comprising a pair of spaced oppositely disposed core and coil` groups, a casing enclosing said groups having a series of vertical slots in the vertical walls there of, and means on said core groups interlocking with the walls of said slots to prevent lateral displacement of said core groups relative to said casing. j

l0. A rectilinear induction .motor comprising a. pair of spaced oppositelydisposed core and coil group's, a casing enclosing said groups having a series of vertical slots in certain of the wall! thereof, a plurality of keys on each of said groups, said keys projecting into and engaging the walls of said slots to secure said groups against lateral displacement relative to said casing.

11. 1n a rectilinear induction motor having coll and core groups, a casing enclosing said groups having a series of vertical slots, the walls of said slots converging toward the inner walls of said casing, keys formed integral with said cores. said keys having enlargedl ends engageable with the converging walls of said slots to secure said core' groups against lateral displacement relative to said casing.

12. In a rectilinear induction lmotor having core and coil groups, a casing enclosing said groups having a series of vertical slots, the walls of each of said slots converging toward the inner wall of saidcasing, keys on said core groups hav- .'110 ing a contour conforming to that of said casing y slots, said keys being engageable with the walls of said slots to prevent lateral displacement o1 said core groups relative to said casing, and means for securing said keys against vertical displace- 115 lment from said slots.

13. A casing, enclosing and-.supporting the field structure of a rectilinear induction motor, com-' prising a pair of spaced parallel elements, means I connecting one pair of corresponding edges 01'120 said elements. flanges terminating the free edges of said elements, the ilanges of one element being in aligned proximity with the correspondingj. ilanges of the other element, said flanges together forming a slot for the entry of a translatable 125 armature into said casing. l ff 14. A casing,enclosing and supporting the held structure of a rectilinear induction motor', comprising a pair of spaced parallel elements, means f connecting one pair of corresponding edges 01'130 said elements, further means terminating the free edges of each of said elements, the further Y' means of one element cooperating with the furi ther means of the other element to enclose one side and the ends of'said casing and together form 135 a slot for the entry o! a translatable armature' intosaidcaslng. A' 

